OSCAR-5: The First Australian-Built Satellite — Michael Spencer

The last few months have seen a flurry of announcements relating to Australia’s space industry. In July 2017, the Government commenced a review of the Australian space industry, and on 29 September they announced the intention to create an Australian space agency. On the same day, the RAAF and the University of New South Wales announced that a contract had been signed to launch three CubeSats into low earth orbit commencing in 2018. These announcements signal the end of the Australia’s official neglect of space operations. As Australia’s small space community of interest prepare to celebrate the 50th anniversary of the WRESAT launch that marked Australia’s first foray into space, it is worth drawing attention to another little-known aspect of Australian space history. In this post, Michael Spencer tells the story of Australis OSCAR-5, Australia’s first satellite, built by a group of University of Melbourne engineering students. Australia may have lacked a space industry, but it did not lack the innovative and inspired individuals who had a vision of an Australian role in space.

On 29 November 2017, Australia’s space community will commemorate the 50th anniversary of the first Australian-built satellite launched from an Australia launch site. In 1967, the Defence Science Technology Group, previously the Weapons Research Establishment (WRE), partnered with University of Adelaide to develop and launch the WRESAT satellite into orbit. WRESAT was launched from the Woomera rocket range atop a spare rocket provided by the US SPARTA research program. While the WRESAT launch is an important milestone in Australia’s entry into outer space, WRESAT was not the first satellite built by Australians; that honour goes to Australis OSCAR-5.

Model of Australis OSCAR-5 [Image Credit: Museums Victoria]

Not long after the USSR successfully launched Sputnik I, a group of American amateur radio operators (“Hams”) developed an amateur-built “Orbiting Satellite Carrying Amateur Radio (OSCAR)” to promote public participation in the new field of space-based communications and technology research. Drawing on support from members and volunteers, donated resources, and the assistance of international governments and commercial agencies, Project OSCAR successfully launched OSCAR-1 in 1961.

After the US-based Project OSCAR agreed to sponsor environmental testing, space launch, and launch operations a group of University of Melbourne students, mostly undergraduate members of the local “Astronautical Society and Radio Club,” were inspired to build a satellite. These electrical and mechanical engineering students had no qualifications or experience in space mission design. They were motivated to make an Australian contribution to amateur radio and enter the brave new world of orbital space missions, but they recognised that their limitations in space systems expertise and experience would drive a relatively simple satellite design. In 1966, on a shoestring budget, this innovative team of amateur radio enthusiasts built Australis OSCAR-5 — the first non-US built amateur radio communications satellite.

OSCAR-5 had four monopole antennas, adapted from commercial-off-the-shelf Stanley measuring spring-steel tapes, extending from its sides for transmitting signals from two beacon transponders. The spring-steel antennas were strapped down during launch and deployed on orbit. It carried horizon sensors for determining the satellite spin-rate and used a magnetic attitude stabilisation control system to adjust the satellite’s spin. A seven-channel telemetry system automatically reported the onboard battery conditions, spacecraft temperatures, and horizon sensor responses, communicated to Ham radio ground stations by using modulations in the beacon signals to represent encoded data.

Passive magnetic attitude stabilisation, to control the attitude and orientation of the satellite, was performed by carrying two bar magnets that would move and align with the Earth’s magnetic field, as the satellite progressed in its orbit. Satellite orientation in relation to the Earth is important to be able to orient the antenna with a favourable antenna footprint for the Ham radio operators on the terrestrial surface. The battery-powered OSCAR-5 transmitted telemetry signals on two purposely designed frequency bands and power settings, at 144.050 MHz at 50 mW and 29.450 MHz at 250 mW, which were in popular use among Ham radio operators, at the time. Since solar cell technology was not readily available, the satellite relied on single-use battery power to operate on these frequencies for 23 and 46 days, respectively.

The students built the radio system and assembled it into a 9.0 kg satellite payload that was a 43cm × 30cm × 15cm rectangular prism with reflective stripping applied for thermal protection. For comparison with similar modern-day university-level project designs, a standard 1.0 kg CubeSat satellite, such as was built for OSCAR-73 (FUNcube-1) that was launched in 2013, measures 10cm × 10cm × 10cm, less than 1/12th the measured size of OSCAR-5, and can be designed to perform the same mission for much longer, following the introduction of solar panel systems for satellites to generate electrical power.

To get these amateur satellites into orbit, the US Air Force and NASA sponsored launch opportunities for university research payloads when spare capacity became available on their space launch vehicles assigned for launching the full-size satellites. Although OSCAR-5 was built in 1966, a launch opportunity did not become available until 23 January 1970. On that date, the student-built satellite was launched atop a Delta-N6 space launch vehicle from Vandenberg Air Force Base Space Launch Complex as a piggyback payload with the Television & Infra-Red Observation Satellite (TIROS-M), a full-sized Earth observation satellite. After launch, OSCAR-5 was released into a circular low-Earth orbit at about 1450 km altitude and 102-degree orbit inclination angle. The orbit orientation was nearly flying a north-south orbit over the north and south poles, enabling access by amateur radio operators in locations across the globe, as it completed one orbit every 115 minutes.

In addition to being the first amateur satellite built outside of the US, OSCAR-5 was also the first to be designed for remote control operations by amateur radio operators. It was designed with an onboard command system to activate the satellite beacon transponder only on weekends, operating between Friday morning to Monday morning, to conserve the battery life and maximise its availability for amateur radio operators, who would normally be operating from their homes on the weekends. The University of Melbourne collected Ham radio contact reports, gained over HF and VHF frequencies, from over 200 operators across 27 countries.

During the timeframe that OSCAR-5 was developed and awaiting a US launch opportunity, the Radio Amateur Satellite Corporation (now known as AMSAT) was formed in 1969 as a not-for-profit educational organisation to foster Amateur Radio’s participation in space research and communication. Using volunteer support from its international membership, donated resources, and the assistance of government and commercial agencies. AMSAT has successfully continued to use Project OSCAR to promote public interest in satellite communications and make space accessible to the students and the general public through Ham communities. Project OSCAR has launched over 90 Amateur Radio satellite missions, since 1961. Today, over 20 Ham radio satellites are currently in operation in orbit. The latest Ham radio satellite, RadFxSat (Fox-1B), designated as OSCAR-91, is a CubeSat joint mission of AMSAT and the Institute for Space and Defense Electronics at Vanderbilt University that was launched from Vandenberg Air Force on 18 November 2017. Initiatives like Project OSCAR and CubeSats provide the technical opportunities to that enable creative and innovative minds to experiment and test new designs for exploiting space and inspire the next generations to build on the achievements of previous generations to advance careers and the continuing uses of space.

Increased public awareness and involvement in space research and missions, and the miniaturisation and increasing affordability of space technology has improved access to space for researchers and academic students, providing a stepping stone to space-related careers and full-scale space missions. Access to CubeSat technology also increases the options available to military users for experimentation, agile designs, and rapid and affordable access to space for shorter duration space missions when compared to the cost of a full-scale satellite mission. In September 2017, the Royal Australian Air Force announced that it had joined with UNSW Canberra to invest in the development of CubeSats for three space missions, with the first mission planned for launch in 2018. These satellites will be configured with re-programmable software defined radios, enabling the onboard mission systems to be reconfigured for different missions while deployed on orbit, improving the satellite’s functional capabilities to be adaptable for multiple or changed missions.

Artist’s impression of a RAAF CubeSat in low earth orbit. [Image Credit: University of New South Wales]

Author’s Note: Although OSCAR-5 has long ago ceased functioning, the global US Space Surveillance Network continues to track it as a residential space object, stable in its low-Earth orbit. OSCAR-5 is identified as Space Catalog number 4321 on a list with an estimated total of about 40,000 tracked orbiting space objects, that listed in chronological order of their launch date. Even though it has expired, OSCAR-5 persists in its low-Earth orbit at about 1450 km altitude as an Australian owned, non-operational, resident space object – awaiting the future intervention of natural environmental forces or an on-orbit event for to it to de-orbit and return to Earth, or not.

Squadron Leader Michael Spencer is currently serving at the RAAF Air Power Development Centre in Canberra, analysing potential risks and opportunities posed by technology change drivers and disruptions to future air power. His Air Force career has provided operational experiences in long-range maritime patrol, aircrew training, and weaponeering, and management experiences in international relations, project management, air and space concept development, air capability development, and joint force capability integration. He is also an Associate Fellow and Section Committee member of the American Institute of Aeronautics & Astronautics. The opinions expressed are his alone and do not reflect those of the Royal Australian Air Force, the Australian Defence Force, or the Australian Government.